Coatings and methods

• US 6,511,701 B1
• Filed: 05/09/2000
• Issued: 01/28/2003
• Est. Priority Date: 05/09/2000
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Divigalpitiya, Ranjith, Chambers, David C., Miholics, Gabriella
• Primary Examiner(s): Beck, Shrive P.
• Assistant Examiner(s): Michener, Jennifer Kolb
• Application Number:
  US09/567,142
• Time in Patent Office: 994 Days
• Field of Search: 427/11, 427/404, 427/407.1, 427/419.7, 427/256, 427/258, 427/261
• US Class Current: 427/11
• CPC Class Codes: B05D 1/28 performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• CPC Class Codes: B05D 2201/02 Polymeric substrate
• CPC Class Codes: B05D 2252/02 of indefinite length
• CPC Class Codes: B05D 7/04 to surfaces of films or sheets producing layered products by applying coatings of pasty or pulverulent plastics B29C41/00

Abstract

A method of coating a polymer substrate with a dry composition comprising particles is provided. The particles have a Mohs hardness between 1 and 2.5 and preferably a largest dimension of less than 100 microns. The particles are buffed on the substrate with an applicator which moves in a manner parallel to the surface of the substrate.

Claims

1. A method of coating a polymer substrate having a surface with a dry composition comprising particles, said particles having a Mohs'"'"' hardness between 0.4 and 3 and a large dimension of less than 100 microns using an applicator pad, comprising buffing an effective amount of said particles on said substrate at a pressure normal to the surface of greater than 0 and less than about 30 g/cm², said applicator pad moving in a plane parallel to said surface in a plurality of directions relative to a point on the surface such that a uniform coating of said particles is provided, wherein the applicator pad moves in an orbital fashion parallel to the surface of the substrate.

2. The method of claim 1, wherein the particles are selected from carbon black, polytetrafluoroethylene, polyvinylidene difluoride, sulfur, tungsten disulfide, polyetherimide resin, zeolites, I-ascorbic acid, silver chloride, silver sulfadiazine, and various amino acids.

3. The method of claim 1, wherein the particles are selected from graphite, molybdenum disufide, tungsten disulfide, clays and hexagonal boron nitride.

4. The method of claim 1, wherein the particles are selected from a mixture of particles selected from the group consisting of carbon black, polytetrafluoroethylene, polyvinylidene difluoride, sulfur, tungsten disulfide, polytetrafluoroethylene, polyvinylidene difluoride, polyetherimide resin, zeolites, l-ascorbic acid, silver chloride, silver sulfadiazine, and various amino acids;

and particles selected from the group consisting of graphite, molybdenum disulfide, tungsten disulfide, clays and hexagonal boron nitride.

5. The method of claim 1, wherein the particles are selected from platelets having a smallest dimension that is less than 10 microns.

6. The method of claim 1, wherein the particles have a Mohs'"'"' hardness between about 1-2.5.

7. The method of claim 1, wherein the substrate is selected from polyester, polypropylene, polyethylene, polystyrene, polycarbonate, polyimide, polymethyl methacrylate, polyvinyl chloride, cellulose acetate, silicone, rubber.

8. The method of claim 1, wherein the uniform coating has a thickness of less than 3 microns.

9. The method of claim 1, wherein the uniform coating has a thickness of less than 500 nm.

10. The method of claim 1, wherein the uniform coating has a thickness of less than 200 nm.

11. The method of claim 1, wherein provided that said composition contains no materials in an amount effective to act as a binder of said particles to said substrate.

12. The method of claim 1, wherein the method is carried out at a temperature at least 20°

C. below the softening temperature of the polymer substrate.

13. The method of claim 1, further comprising the step of applying a subsequent coating over the uniform coating of particles.

14. The method of claim 13, wherein the subsequent coating is a hardness enhancing coating.

15. The method of claim 1, wherein said uniform coating is located at selected regions of the coated surface of the substrate.

16. The method of claim 1, wherein the particles comprise buffing aid particles and exfoliatable particles, wherein the buffing aid particles have a low affinity for the substrate to be coated and a low affinity for the exfoliatable particles.

17. The method of claim 16, wherein the buffing aid particles are selected from the group consisting of encapsulated dye particles, Methyl red dye particles having a CAS number of 493-52-7, Methylene blue dye particles having a CAS number of 75-09-2, Perylene Red pigment, Rhodamine B dye having a CAS number of 81-88-9, Malachite green oxalate having a CAS number of 2437-29-8, and Azure A dye having a CAS number of 531-53-3.

18. The method of claim 16, wherein the buffing aid particles are selected from the group consisting of magnetic toner particles.

19. The method of claim 1, wherein the particles comprise buffing aid particles and exfoliatable particles, wherein the buffing aid particles have at least some affinity for the exfoliating particles.

20. The method of claim 19, wherein the buffing aid particles are selected from the group consisting of copper phthalocyanine having a CAS number of 147-14-8, Rose Bengel Stain having a CAS number of 632-69-9, Furnace Black carbon particles having a CAS number of 1333-86-4, Azure B dye having a CAS number of 531-55-5, Methyl orange dye having a CAS number of 547-58-0, Eosin Y dye having a CAS number of 17372-87-1, New Fuchin dye having a CAS number of 569-61-9, and ceramic particles.

21. A method of coating a polymer substrate having a surface with a dry composition comprising particles, said particles having a Mobs'"'"' hardness between 0.4 and 3 and a large dimension of less than 100 microns using an applicator pad, comprising buffing an effective amount of said particles on said substrate at a pressure normal to the surface of greater than 0 and less than about 30 g/cm², said applicator pad moving in a plane parallel to said surface in a plurality of directions relative to a point on the surface such that a uniform coating of said particles is provided, wherein the applicator pad moves in a random orbital fashion parallel to the surface of the substrate.

22. The method of claim 21, wherein the particles are selected from carbon black, polytetrafluoroethylene, polyvinylidene difluoride, sulfur, tungsten disulfide, polyetherimide resin, zeolites, I-ascorbic acid, silver chloride, silver sulfadiazine, and various amino acids.

23. The method of claim 21, wherein the particles are selected from graphite, molybdenum disulfide, tungsten disulfide, clays and hexagonal boron nitride.

24. The method of claim 21, wherein the particles are selected from a mixture of particles selected from the group consisting of carbon black, polytetrafluoroethylene, polyvinylidene difluoride, sulfur, tungsten disulfide, polytetrafluoroethylene, polyvinylidene difluoride, I-ascorbic acid, silver chloride, silver sulfadiazine, and various amino acids;

and particles selected from the group consisting of graphite, molybdenum disulfide tungsten disulfide, clays and hexagonal boron nitride.

25. The method of claim 21, wherein the particles are selected from platelets having a smallest dimension that is less than 10 microns.

26. The method of claim 21, wherein the particles have a Mohs'"'"' hardness between about 1-2.5.

27. The method of claim 21, wherein the substrate is selected from polyester, polypropylene, polyethylene, polystyrene, polycarbonate, polymide, polymethyl methacrylate, polyvinyl chloride, cellulose acetate, silicon, rubber.

28. The method of claim 21, wherein the uniform coating has a thickness of less than 3 microns.

29. The method of claim 21, wherein the uniform coating has a thickness of less than 500 nm.

30. The method of claim 21, wherein the uniform coating has a thickness of less than 200 nm.

31. The method of claim 21, wherein provided that said composition contains no materials in an amount effective to act as a binder of said particles to said substrate.

32. The method of claim 21, wherein the method is carried out at a temperature at least 20°

C. below the softening temperature of the polymer substrate.

33. The method of claim 21, further comprising the step of applying a subsequent coating over the uniform coating of particles.

34. The method of claim 33, wherein the subsequent coating is a hardness enhancing coating.

35. The method of claim 21, wherein said uniform coating is located at selected regions of the coated surface of the substrate.

36. The method of claim 21, wherein the particles comprise buffing aid particles and exfoliatable particles, wherein the buffing aid particles have low affinity for the substrate to be coated and a low affinity for the exfoliatable particles.

37. The method of claim 36, wherein the buffing aid particles are selected from the group consisting of encapsulated dye particles, Methyl red dye particles having a CAS number of 493-52-7, Methylene blue dye particles having a CAS number of 75-09-2, Perylene Red pigment, Rhodamine B dye having a CAS number of 81-88-9, Malachite green oxalate having a CAS number of 2437-29-8, and Azure A dye having a CAS number of 531-53-3.

38. The method of claim 36, wherein the buffing aid particles are selected from the group consisting of magnetic toner particles.

39. The method of claim 21, wherein the particles comprise buffing aid particles and exfoliatable particles, wherein the buffing aid particles have at least some affinity for the exfoliating particles.

40. The method of claim 39, wherein the buffing aid particles are selected from the group consisting of copper phthalocyanine having a CAS number of 147-14-8, Rose Bengel Stain having a CAS number of 632-69-9, Furnace Black carbon particles having a CAS number of 1333-86-4, Azure B dye having a CAS number of 531-55-5, Methyl orange dye having a CAS number of 547-58-0, Eosin Y dye having a CAS number of 17372-87-1, New Fuchin dye having a CAS number of 569-61-9, and ceramic particles.